Cal. Gov. Code § 51238.2
Mineral extraction that is unable to meet the principles of Section 51238.1 may nevertheless be approved as compatible use if the board or council is able to document that (a) the underlying contractual commitment to preserve prime agricultural land, as defined in subdivision (c) of Section 51201, or (b) the underlying contractual commitment to preserve land that is not prime agricultural land for open-space use, as defined in subdivision (o) of Section 51201, will not be significantly impaired.
Conditions imposed on mineral extraction as a compatible use of contracted land shall include compliance with the reclamation standards adopted by the Mining and Geology Board pursuant to Section 2773 of the Public Resources Code, including the applicable performance standards for prime agricultural land and other agricultural land, and no exception to these standards may be permitted.
For purposes of this section, "contracted land" means all land under a single contract for which an applicant seeks a compatible use permit.
Ca. Gov. Code § 51238.2